Improved expanding mandrel



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DAviD L ALLEN OF-WILLIAMSPORT, PENNsvLvANIAJ Letters latent'No. 95,065, dated September 21, 1869.

.t ow- .IMPROVED EXPANDING- MANDREL.

The Schedule refen'ed to in these Letters Patent and making part of the same.

To all 'whom it may concern: n v I Y Be it known thatI', DAviD L. ALLEN, of tile city of YWilliamsport, inthe county of Lycoming, and State of Pennsylvania, have invented a new-and useful Improvement in Expanding Mandrel-Ghucks;. and I do `hereby declare that the following is a full, clear, and

exact description oi' the construction and operation of the same, reference being had`to.the'accompanyingl whichV y Figure 1 is a'viewof themandrel', complete.

drawings, making a partei' this specification, in

Figure 2 is a section of the mandrel, with cones,

screw-nuts, and expanding chucks removed.

' dFigure 3 is valso a section, with cones, screw-nnts, f

and expandingV chucks in place, and showing the man- .ner inwhich `the latter are expanded.

Like letters in the'igures of the drawings indicate like parts. 1

My invention consists of a solidy mandrel, Aprovided with expanding chucks, in combination with cones and screw-nuts, the said expandingchucks being so con,-

, structed asto lit and move in grooves ofthe cones, so that, by screwing up the nuts, the cones will cause the l clined ends. Y

' Each chuck fits sufficiently loose in slots a, connnu`v l nicating with `the bored ends` of the mandrel, 12o-be freely movable therein.

The outer under ends of the chucksaremade to tit' the inclined sides `of the' cones,leach chuck tting a groove, d, of the cones, and so constructed as to be held, and move freely therein, by means oflguides, the edges of which will projectfrorn the sides ot' the grooves, and fit in narrow grooves-in the sides of the chucks. l

` The ends of the slots in the mandrel are inclined, to correspond with the inclined ends of the chucks; thus the chucks work up anddown in the grooves el of the cones, and through the slots, according to the direction in which the-nuts are revolved.

4Upon thefturned-down ends EE of' the mandrel are provided screw-threads b b, upon which the screw-nuts `The cones'are so connected with thenuts, bymeans `of a groovedV joint, that .they willlnove inthe bores of the mandrel, and act upon' the chucks, by revolving l the nuts. g g Y To hold the work desired to' be turned, itis placed over the mandrel, and the chucks expanded until they fit the hole thereof', the chucks having 'an oblique movement, which, in combination with the'con'es, gives them a more solid basis, so that the'workwill be held more rigidly while being turned. 'l

The chucks arevariangedat equal distances apart .around the mandrel, Vnext to the ends thereof.

Having thusV fully described my invent-ion, What I claim therein as new, and desire to secure by Letters Patent, is-,

The screw-nut C, cone B, and chucks A, constructed and combined asthercin described, in combination with the sold mandrel, recessed'at eachend, and with screw- -tlneadextremities E, substantially as set forth.

DAVID L. ALLEN.

Witnesses: y

GEO. A. Camini', Ons.` T. HUsrox. 

